To better quantify the impact of different window opening models in comparison to ventilation techniques a multizone ventilation model, incorporating the CO2-production of the inhabitants, was developed, using Comis-Transys. The reference model represents a free-standing dwelling in which infiltration is the only source of fresh air. Through a series of simulations natural ventilation systems (standard, user controlled or CO2-based demandcontrolled), air-tightness techniques and/or window opening models (deterministic or stochastic) are added.
Ventilation and comfort assessment of buildings is not a new practice in post occupancy evaluation (POE) of buildings. Most evaluations have been based on perceived assessments by the occupants collated through questionnaires asking for a Yes/No response or qualitative scale rating. While this study does not deal with a POE survey, it was initiated by the lack of comfort and overheating complaints of the occupants of the subject university building.
Natural night ventilation and an earth-to-air heat exchanger are applied in the low-energy office building ‘SD Worx’ in Kortrijk (Belgium). Temperatures measured during summer 2002 are used to discuss the operation and cooling effect of these passive cool
In the 1990's, concern about global warming has resulted in a resurgence of interest in naturally ventilated offices. The Belgian climate is particularly well adapted to apply cooling by natural ventilation. Indeed, except for a few hours a year, outdoor air temperature is lower than indoors. Lots of office buildings have no atrium or chimney to benefit from any stack ventilation. But natural ventilation can nevertheless be organized with only frontage windows either by single-sided ventilation or by cross ventilation.
The use of natural ventilation systems continues to be a popular feature in low energy, sustainable building design. One feature of natural ventilation is that, depending upon the prevailing climatic or thermal conditions, the airflow through a ventilator can be bi-directional. Aerodynamically, the ventilator, depending upon its construction, may not perform in the same way for the two different flow directions.
An experimental campaign was organized during the summer period 2002 in Athens, in the framework of the European RESHYVENT Project. The main purpose was to indicate the impact of the urban environment on the natural and hybrid ventilation air flow process in urban canyons. Field and indoor experimental procedures were carried out in two urban canyons, presenting different geometric and urban features. The experiments were organized for more than three consecutive days within three different periods in summer and on a 24-hour basis.
The design for the new Federal Building for San Francisco includes an office tower that is to be naturally ventilated. The EnergyPlus thermal simulation program was used to evaluate different ventilation strategies for space cooling and rationalize the design of the faade. The strategies include ventilation driven by different combinations of wind, internal stack and external stack. The simulation results indicate that wind-drive ventilation can maintain adequate comfort even during hot periods.
Considering the natural ventilation, the thermal behavior of buildings can be described by a linear time varying model. In this paper, we describe an implementation of model reduction of linear time varying systems. We show the consequences of the model reduction on computing time and accuracy. Finally, we compare experimental measures and simulation results using the initial model or the reduced model.
Present international standard for thermal comfort such as ASHRAE Standard 55 and ISO 7730 were developed to serve as a guideline for moderate thermal environments e.g. mechanically airconditioned spaces [CEN ISO 1995]. Recent thermal comfort studies had reported that some discrepancies were observed in its application for Naturally Ventilated (NV) buildings in hot and
The necessity of focus on more large integration of passive concepts for indoor climate conditioning is today a reality. Through this study, a contribution to fill the lack of useful design guidelines for natural ventilation is proposed, in order to develop the passive ventilation systems implementation. Besides a methodological approach, the paper proposes conceptual tools. The implementation of a natural ventilation strategy includes the envelope building design, the indoor spaces layout and the
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